Add Aikido Safe Chain workflow for malware protection

Co-authored-by: ryota-murakami <5501268+ryota-murakami@users.noreply.github.com>

Author: Copilot

.github/workflows/malware-safe-chain.yml

@@ -0,0 +1,28 @@
+name: Malware Safe Chain
+on:
+  push:
+    branches:
+      - main
+  pull_request:
+    branches:
+      - main
+jobs:
+  safe-chain:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+      - name: Install pnpm
+        uses: pnpm/action-setup@v4
+        with:
+          version: 10
+      - name: Use Node.js
+        uses: actions/setup-node@v4
+        with:
+          node-version: '22'
+          cache: 'pnpm'
+      - name: Install Aikido Safe Chain
+        run: npm install -g @aikidosec/safe-chain
+      - name: Setup Safe Chain for CI
+        run: safe-chain setup-ci
+      - name: Install dependencies with Safe Chain protection
+        run: pnpm install